On 16/11/2020 09:16, Mike Halmarack wrote:
Some of mine are carpet to carpet, others are carpet to tile.
With several of them the carpet has moved/shrunk, exposing a ragged
edge. I would like to replace the aluminium strips with wider ones to
compensate.

I've tried to gently lever one or two up but they seem very resistant.
The floor beneath is concrete to which the strips seem very firmly
fixed. Not having much idea how to remove and replace them I'd much
appreciate some advice.

It's fairly easy to make a hardwood threshold strip and then it could be
any size you want - they look much better than aluminium and can be
stained/varnished/oiled as required. I've been making mine out of
reclaimed oak skirting.
If you haven't got the tools a local woodworker would do it in a few
minutes.