The trick here is to be gentle! The strips will have a plastic insert which can be removed by inserting a small screwdriver into one end and lifting to strat it off - the rest will pull out.
What you will find then, is lots of small screws that hold the alloy strip down. Undo these, some may be awkward - in which case, use the small screwdriver to lift the screw head as you unscrew. Gently remember!
Next stage is to lift the strip - this is where you have to be careful not to bend it. Gently lift, pry with a covered end screwdriver so you don't damage the fibreglass (masking tape over the tip) and genlty work your way round until loose. This is the messy bit mind! Trim any selaer from the strip with a knife blade to free it from the old sealer bed. Store somewhere safe.
Using the covered ended screwdriver or a blade if you are competent and gentle, remove the old sealer bead from the join, and again on the ally strip - making sure you do not apply to much pressure and bend it. It will be messy but fairly simple.
After this clean with some thinners or similar, dry off. Make sure you know where the screw holes are by using a marker such as a peice of tape, pencil line or similar - as long as it polishes off! lol! Take some new non drying seam sealer, and reapply a bead the length of the join - anywhere the join as lifted you need to apply underneath. Offer the ally strip back into position - use an assistant if need be. Pop in some screws top middle and bottom, and just start them off to position it.
Then just put all the screws in and screw done alternately and evenly along the strip. The sealer may ooze out, this can be cleaned off later with mutton cloth soaked in thinners. Once srcewed up, them you can reseat the plastic centre moulding - use a small blob of sealer every so often as a means of sealing the strip down so it doesn't fly out as you drive.
