There are several ways to approach nail clipping.
1 take them to a glider experienced vet and let them do them it usually costs around 12-18 bucks.
2 get a mesh nail clipping pouch, their nails poke through the holes and you just clip away, but you have to be able to get the glider IN the pouch for it to be effective and some gliders like my lil bratty female refuse to go into it.
3 use a regular pouch, bribe them with mealie worms and pick up a foot and clip it.
Everyone has their own techniques that work for them and their gliders, you will have to find the best way for you and yours.
For me, I have found that a single layer open pouch works best, I play with their feet when they are asleep to get them used to their feet being touched without being clipped.
I show the gliders the nail clippers, let them smell them, touch them, and see what I'm about to use. I used to try to hide the clippers from them but that just seems to stress them out. When they can check out the clippers it seems to let them know I'm not trying to hurt them.
Then I just pick up a foot and clip until the gliders show stress then I stop, wait a while till they relax and do the next foot and so on. I clip nails in the late after noon when mine are the most sleepy. At night they are to active, in the morning they aren't quite enough asleep.
Glider nails do have a quick so you do have to be careful not to cut to far, they will bleed. So before you even begin get everything you need in one place.
have treats easy to reach
have clippers on hand
have a small container of cornstarch it will stop the bleeding if you cut to far.
have a good light, I use a LED head light so I don't have to hold it.
and if you need to get some reading glasses to help you see the nails better for me this was the most valuable tool for nail clipping and my headlight.
In the second pic it shows the hind foot in the left hand corner. Only 2 nails on the hind feet need to be clipped. The two long skinny nails on the toes that look stuck together are their grooming nails, those do not need clipped unless they are extremely long. They don't usually get those nails snagged on anything.
Now on this last pic, the last diagram is way to short for glider nails, the diagrams are for dog nails, but for over grown glider nails the same principal applies. Diagram 5 is probably about where a gliders nails should be with regular nail trimmings to shorten the quick.
These are the basics...