When i started riding fixed gear i didnt know about greasing my threads so 2years later my lock ring is seized. Is the way that i can remove the lock ring with out striping the threads? thank you.

Try PB Blaster, let it soak. I would think a lockring tool would be best for this job but you can always try the old hammer and screwdriver.

If the cog is seized too, use the Rotafix method in reverse: https://204.73.203.34/fisso/eng/schpignone.htm

If your lockring is steel and your hub threads are aluminum, pour ammonia all over it a few times and give it a chance to really soak. The fumes will punch you in face, so do it outside or somewhere ventilated. Ammonia attacks the bond that forms between steel and aluminum. PB blaster or other penetrating oils work with a steel/steel thread interface.

Also, heating will not be as useful as you might think because aluminum (the hub) expands more with heat than steel does.

I don't like to use screwdrivers as lockring punches because they're too sharp and tend to cut into the ring. I still have a specially dulled punch with a nice square edge I made decades ago for use on the track.

Also don't try removing a tight lockring by beating away at a single notch. Rotate the wheel and try all the notches because the ring distorts, and by taking a shot at all the notches you increase the odds of using the flex to break the bonds all the way around. The same applies when setting it, tighten form 3 notches by degrees to make sure it's really tight.

PB Blaster it, let it sit for a while (15 minutes, maybe),
remove both crank arms, put the whole bike up in a bench
vise with soft jaws (copper or aluminum), the vise should
be grasping the non drive side spindle taper.

Take a hammer and drift (or a chisel, if you can throw away
this lock ring and use a different one) and strike it forcefully
and with great vigor with the drift in each of the notches
as described by FB. You need to angle the drift so that your
force goes tangential to the BB, not radial, in the counter
clockwise direction.

Curse if you need to.

Your description relates to a bottom bracket lockring removal. The OP said the bike is a fixie so I believe his problem is the lockring on the rear hub. Also, if it is the hub lockring, is he aware it's left hand threaded.

the Type of hook spanner for cup and cone BB adjusting cup lock-rings,
is what you need to remove a track hub lock-ring..

But, NB, the threading of the hub lock ring is LEFT Hand threaded ..

might be same, [some BB tools ala Park, have 1 hook .. that should work.
others have 3 pins .. like to better to engage lock ring,
Ala Campag tool to lockrings being Campag parts

Both excellent points, which I shall leave to the OP to clarify.

I also didn't bother reminding the OP that lockrings have left hand threads, but I'm starting to think that it's possible we're giving him too much credit. (no offense intended to the OP).

He's been riding fixed for two years, and possible hasn't ever changed a sprocket. If a dealer installed the sprocket there's no reason for him to know or remember that the lockring is counter-threaded.

To the OP, before you chisel the ring in two, check that you're driving it to the right, opposite to the way you'd remove a sprocket.

i know its left hand thread since i installed it my self. I tried pb blaster it still failed can i heat it up with a heat gun and try or that would destroy the hub? fyi im using a homemade lock ring tool like this https://toolmonger.com/wp-content/upl...iers72-450.jpg and i have a formula lockring Should i just go out and buy the proper tool? thank you

That's a decent tool for the job, but it has a drawback. As you work harder, you tend to squeeze the lockring, which makes it harder to turn. Try using some touch, holding the tool only tight enough that it doesn't slip off.

You might also try using it to flex the ring, Squeeze the ring hard to flex the ring back and forth by switching notches.

BTW- In my experience, impact does a better job separating frozen parts, so you might want to give the chisel a shot. Since you're good with the grinder, shape the end of the chisel to meet the notch when it's set almost at a tangent.

Heat it up pretty good-- enough so a wet finger sizzles on it-- and hit it with the PB Blaster again. As the metal cools, capillarity draws the oil further in. Try removal again, if it doesn't come off easily, do another heat/soak cycle. It might take 2 or 3 or more, and that's OK. Time is cheap. Heating isn't entirely useless, because the metals expand and contract at different rates and a few cycles of this help break any corrosion bond.

You will have to overhaul the hub bearings, though, as the heat drives off some of what makes grease, grease. No big deal, though, it's already off the bike and after 2 years it's probably due for an o/h anyway.

Based on considerable experience with extremely stobborn nuts & bolts on motorcycles, the only thing I can offer here is use of a different type of thread loosening liquid. When I encounter difficult removals, I use a 50/50 mixture of automatic transmision fluid and acetone. The acetone creates a very good capillary effect carrying the ATF into the threads. Let that sit for an hour or two and then use your lock-ring tool or hammer & punch.

A hammer and punch, or a j shaped lockring tool will give the best result as you'l be able to use impact force(if you know what I mean, think air impact gun) to losen the bond.