Here are two easy tips for you:

1. If your pegs are too loose, rub some Rosin on them (yes, the same Rosin you use for your bow), and that'll make the trick to make them "stick" to their hole.

2. If your pegs are too hard to turn or stuck, use body powder to loose them up (yes, the one you may use after a shower or bath)

I hope that helps!

Best,

Fabrizio