Sunnas welcome to the forums.
I dont have the Pavla kit but I have other kits that are similar with vac bubbles and I have always had trouble with them.
If you are experienced with VAC kits or Falcon canopies, ignore everything below.
If you are not used to working with VAC canopies one of the easier ways to seperate them from thier original sheet plastic is with a pair of curved fingernail scissors. Work slow and fit multiple times. YOu may find that you need to shim or reduce the width of the fuselage to match the bubble once it is cut out. You really cannot change the bubble, but you can change the fueselage to match by sanding or shimming.
Use thick white glue (PVA) or Model Master Windowmaker to install it. I wouldnt want to take a chance with supeglue fogging it. Once installed it should be nice and sturdy, even if it feels flimsy when you cut it out.
HTH helps some, welcome to the forums!
David
Build to please yourself, and don't worry about what others think!
TI 4019 Jolly Roger Squadron, 501st Legion