Cabrio 1985 roof seal removal advice

I wish to remove the big fat car-to-roof-fabric rubber seal that goes from side to side from a-pillar to a-pillar, it's about an inch above the windscreen.
I also want to replace the metal thingy that the roof-handle hooks lock into.
On each side of top of the a-pillar, both facing inwards, there's plastic bungs/caps, how do I get that out?
Again, at the top of the a-pillar, facing rearwards, there are small metal chrome thingies, look a bit like a pop-rivet or an allen bolt, how do they come out?
I've got a photo.
Anyone got instructions for replacing the big rubber and roof hook socket, please. 
 

yepper.



The top arrow piece 19 is pushed up, and will come off the latch. be gentle

The side arrow
Push the Pin through in the middle of the clip on the side. it will fall so keep you hand under it.
Now the side cover will come off and expose the second screw that you have to remove.

If you carefully lift the edge of the "a" pillar seal you should expose the second screw.  The A-Pillar is Pop Riveted so you will have to drill it out, and have a replacement to go back.

That's great quick info. Will try it now. Many thx.

The upper "a" pillar seal that runs left to right, may be glued in, so take care removing it.