trouble with wallpaper

[gregndebi]

how do I reattach the edges of my wallpaper ?

[archbishop]

I use a pritstick.

[Dusky]

There are products available, pretty much anywhere you can buy wallpaper, specifically for re-doing edges.  Squeeze it sparingly but evenly under the separated part, rub carefully towards the lifted side with a clean finger to push it under, go over it with a seam roller and wipe away the excess that's squeezed out.