I am uncut, and massive, so I have a similar issue. Generally, I find that pros will want to apply it themselves. But once in a while, it is my job. What I do is:
- Right-hand pinches condom, applies to head, fingers roll it down.
- Left-hand two fingers hold shaft, and hold foreskin back if neccessary. Other two fingers and thumb roll it down.
The key is to pinch out the air and roll it down, not try and shove it through.