Hey,
I used to crack this bot for my lil bro its quite easy lol.
The classes that you needed to modify back then where.
u/bV.class and u/ck.class
Just so you know every version this might change it probably wont happen every version but probably with big changes.
Easy way is to detect what class has the host it connect to in it.
Decompile it remove all uneeded code return true and 999999 for some functions.
Recompile and just reuse it for the next version if the class names havent switched.
I made a patcher back then but probably no longer working

.
Why i stopped was because of the chapcha enabling if i remember correctly.