Mike Halmarack explained on 16/11/2020 :
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.

They are probably glued down to the concrete and likely a type where
the carpet is pushed into a slot which has a sharp series of tangs to
retain the carpet at either side.

Rather than removing the existing strip, you might find it more
sensible to fit a flat strip joiner over the top. Drilling and fixing
with screws through your existing strip.