How to tell if Hub Cartridge bearing is dead.
 

Formula hub cartridge bearing.

I was going up a steep hill climb, and all of a sudden it sorta got harder to pedal.

Front or rear? Hard to say the condition of a bearing without inspecting it. At least access it and feel how it rotates with your fingers, if it's rough just pull the seal off and clean it and regrease it and go from there...otoh could just be your legs.

rear. WOuld you guys say that cone wrenchs are completely nessasary? you can't get away with a standard wrenchs?

Sounds pretty troll-y to me, usually the hills make it harder to pedal.

Perhaps the hill got steeper while you were climbing? :)

The need for cone wrenches depends on the hub design - I have a set of sealed bearing hubs that do not need cone wrenches, and a set that do need cone wrenches. Generally, cone wrenches are used to hold the bearing tension adjusting component (in cup and cone hubs it is the cone) while you tighten a locknut against it. If the hub is designed to use cone wrenches then, yes, you 100% need cone wrenches. You can make a 'cone wrench' by grinding a standard wrench very thin on a bench grinder, but actual cone wrenches are usually $6 - $10 so it is much easier to just buy the purpose-built tool. Offer to mow an old ladies lawn for the extra $6 if money is tight.

As for bearings needing replacement, take off the wheel and spin the axle - is there excessive drag? Is there a bearing that is obviously not turning with the axle? To be sure if they need replacement you really need to remove and inspect and check for play or roughness.

IM not a 'trolling' you. THe wheel seems like it has extra resistance on it now. If I was gonna troll, i'd make it alittle more interesting.

When I spin the axle, if it doesnt make a nasty noise, could it still be bad?

Sure. Spin the axle with your fingers to feel for drag and roughness. Cartidge bearings are so cheap, it's not worth taking chances.

If the axle rotation is stiff, the bearings are bad or (unlikely) the axle is bent. Cartridge bearings from a bearing house are a couple $. If that isn't it, make sure your brake pads aren't rubbing your wheel. This is usually due to a wheel shifting in the dropouts.

If the axle is spinning with no play/roughness it's probably fine...but don't just listen with your ears, feel with your fingers (take the wheel out of the frame). You might not have an axle bearing problem but a freehub problem (assuming it is a freehub).

Track Hub. soooo.....Take axle out, knock em out with a screwdriver, then use a socket to punch the new ones in?