What's the best way to eliminate weight on the back end
 

I'd like to lighten the back end of my 2004 or 5 GT Zaskar Team hardtail. Any suggestions on what would give me the best weight savings and what would be the cheapest route to go?

Here are some stats:
A sram X.O rear derailur
Mavic x 227 rims- dont know the spokes, the hub says shimano but also has motion control sticker?
The cassette is sram pg990 34t powerglide two

dont know what else is there?? im a noob any help would be great

Lighter wheel, closer range cassette, turn it into a single speed, just a few ideas.

Lighter tire would make a big difference.

Trim the engine down some?

Eat less junk food.

i weigh 155lbs, if anything i should eat more junk food

Where would i find my current tire weight?

ritchey zmax 2.1

You are not going to be able to shed all too much weight back there without effecting durability or performance. If any route I'd replace the wheelset. Go for something like a crossmax SL.

So you WANT to be heavier. Blimey... why? Or is it just that your all flab atm and would like some muscle to go with it :p.

Look here for tyre weight.