I hope the forum can offer me some ideas about this situation I have with a MK2 wreck.
I'm wanting to get the prop shaft removed BUT...
I failed to crack the nuts on it before removing gearbox and engine. The car is on stands with no wheels. Open diff so if i jam one hub the other one spins. What would be the best way to lock the prop so I can remove it? I have a pair of wheels that can go on but hard getting under the car when it's on the ground. Thanks

Do you have any old wheels/tyres you can put under the cars wheels? Make sure the inside of the wheels are facing up so the tyres on your car sit in them (so nothing can move etc). Put some jacks under too if you can fit them just as a safety perhaps.
Should just give enough height to crawl under? just maybe... 
 
Also do you have the handbrake on?

Do you have an impact gun?
 
You could undo one with a spanner on the oposite bolt.  Not sure about the last one though.
 
You could also put long bars between the hub bolts and floor so they stop them moving and then undo the bolts.
 
Good luck and post up the answer.
 
Matt
 

Big screwdriver should fit through the U/J, or at least jam into it so you can prevent prop turning

I have a Panasonic impact driver. The bolt heads are very close to UJ, I could use an adaptor to get  3/8 socket. it did cross my mind. The long bars from hubs to body might work but working alone I'm sure they'll keep popping out whilst under the car.
Tried a big flatblade through the UJ today but need something longer to jam in the floor tunnel. Even then i want to keep the shaft in good condition so not sure about stresses on the UJ. Prop flange bolts are very tight.
EVO I do have some wheels that might offer clearance but like you've said I want to make damn sure the car doesn't move when I'm hangin off the ratchet
 

You could put the engine back in!
 
Matt

Bwahahahaha! No thanks :(
I'll give the impact driver a go like you suggested Matt.  I think one arm gripping the prop and free hand on the bolts will do it.

One of these with an extension bar

robertverhey

Big screwdriver should fit through the U/J, or at least jam into it so you can prevent prop turning

 
+1
not  a big deal at all
 
Woz

Screw driver through the UJ has always worked well for me when I have been silly enough to forget to loosen before disconnecting handbrake or other bits... Impact driver should do it easily...