how much do I put in?

Okay. But yeah the crank case or whatever. Right side of the motor with the kick start
 
it says it on every side of bottle.
either drain bottle till it reads 650ml or do the math
1qt is 946ml so about 3/4 of 1qt but measure it:)
 
I have 250ml of crankcase oil. Would it hurt to put some transmission oil or something like that in it? Haha just wondering
 
650 is the amount if you drain. A rebuild will take a little more as there is no residual oil laying in the case, gears, bearings.

Shell Rotella T5 is a good oil, faily economical. Diesel rated, SM, JASO.