Replacing Interior cab wall in upper bedroom

I would fasten the panel to the studs and then use a couple 2x3s to make a brace,to hold the edge in place, the make another T brace and move it along the curve in small increments, stapling as you go. When it gets hard to bend, leave the brace against the panel for a time so tht the panel takes a set, it may take a couple of days to get it to bend to the curve of the studs but the panel will slowly bend into place.

Because you can't see what is happening and if the panel it conforming to the bend before you start attaching the panel make a template that matches the curve to check the bend as you go.