I don't know how to do it so that is why I'm asking.

 

Properly?

Take it to a shop that does A/C work and have them evacuate your remaining R12 into a compatible machine.

The other way? I'm not saying because it obvious, as well as EXTREMELY bad for the enviroment and *technically* illegal.

 

Very strong vacuum pump. Not a cheap one like most. But you're better off just paying a shop.

Do not refill with r-134a. Convert internals to accept r-134a first (not just external fittings like the garbage most places sell). Or better yet get some Freeze-12 or HC-12 to do the refill. Make sure the A/c shop will do ti.

 

Take out your bigass alligator knife and cut the line.
And DON'T inhale!

 

As I said, its obvious.

And if you don't use an alligator knife - then it won't work right

 

use the gauge which has three lines. Red, Blue and Yellow.
Yellow connects to the empty r12 tank. Red connects to high side and blue connects to low side. Open the red connector while u are running ur engine with ac on. Read the gauge carefully. Most of the r12 will go to the tank be careful while u are doing this. there will be some of the R12 u need to use vacuum pump.