I was debating buying a new mtb or rebuild my 2003 Giant Rincon and I decided to do the latter as I never did a bike tear-down before and it would be a good learning experience. I started by removing the ancillary parts and the front fork. I learned it has loose ball bearings in the headset and took off the bottom race with a flathead screwdriver which is generally advised against, ha. I cannot take off the cranks myself and I don't know what to do with the drivetrain. It has the stock 3x8 Alivio groupset which is incredibly relaible but not particularly quick. I don't know if I should get a new 3x8, go to 2x10 (if it will fit), or what. The fork I am getting is aRockShox Recon Silver which is about $190. I would like the groupset to stay under $200. I think the outcome can be a really nice build and I get to keep the frame I've been using since I started riding. Aside from that it's getting new tires, pads, and maybe a new, wider handlebar.
Some terrible phone pictures: