Raising the rear of the car will reduce the amount of oil lost, but it's unlikely you'll get the tail high enough to completely eliminate it.
All I can suggest is, get the tail as high as you can, catch the spill in a nice clean container and put the collected oil straight back in! Unless it looks awful, in which case, change it all again!
Normally i'd say drop the oil out first, drain the box! But this is a Sprint and knowing what a PITA they are to fill, refilling could be the longest part of the job! So I won't!!
No quick fix on the reverse light switch either, i'm afraid. And with access to it as bad as they are, it's probably tunnel out to change it, though the leak is often from the fibre washer between switch and gearbox, the access is the same and you might as well fit a new switch regardless!
Steve