What do I with cold feed pipe, system conversion?

Hi everyone looking for a litttle advice. I am converting grant vortex pro boiler to sealed system.

I’ve pulled the boiler out but am not sure what to do with the cold feed for system old system, it goes down into the concrete floor. Am I ok just cutting it low and capping it or do I need to break out the chisel?

Please see pic


Pipes are

1, cold feed (from loft tank)

2 central heating feed

3 central heating return

4 hot water to washing machine (from hot tank)

5 central heating return

6 central heating feed


Many thanks

James