Air Con retrofit - solution!

[Essex2Visuvesi]

Unless your A/C system has been purged, I'd be tempted to leave that part to the pros.
Or, have it emptied, then swap the condenser, then to get it filled professionally

It is actually an offence to knowingly vent an AC system to atmosphere

[Bossworld]

Yep, got a local specialist but at £35 an hour it's going to wait til next Spring, if ever.