Help fixing a 99 Intruder 1500

I just got my dad’s old Suzuki intruder out of storage, and I’m trying to fix it. The transmission slips into a false neutral, and we think it’s because the clutch is gunked up after years of not being used.

This is my first real mechanical work, if I have some obvious questions, but is there a way to totally drain the gas tank and the transmission without dismantling the bike entirely? If so, does anyone have a guide they can point me to for this?

@aakekabhimujhejaanbr - There should be a petcock of some style under the gas tank. removing the hose between that petcock and the carburetor will allow you to drain the gas tank. The engine and transmission should have a drain plug as well. Make sure you locate the proper fluids to refill the engine and transmission before you drain them.

A shop manual is likely available online, and is always a recommended purchase, as it will show step by step directions for tasks like these and also give the specs for adjusting and replacing parts.