Reversing an interior door

[nht1]

Hello,

I'm a beginner when it comes to building, but I've decided to reverse an interior door and need some help with which building materials to purchase. As you can see in the pictures, the aerated concrete is crumbling. The house is from the 40s.

My plan is to remove the frame and then rebuild the "wall" with what? Plasterboard, coarse filler, or what?

Then I thought about attaching the frame with construction foam since I guess screws won't work. I've read that someone did it this way. Do you think it will hold?

Grateful for tips for a beginner

 

[nht1]

I've been told I should use karmskruv.. but does it work if everything falls apart?

 

[Vante]

Karmhylsa and lättbetongskruv.

 

[nht1]

There is still a lot to tweak. Took a picture that shows what it looks like around most parts of the door.

We'll see when I cut out the frame.