I bought a Titan breaker from Screwfix a few years back, wasn't hugely expensive and it doesn't get used much but it was well worth the money.
They don't sell Titan branded ones now but they still sell cheap ones.
For the record, this cut through it like butter, the cut was outlined with SDS drill holes first and basically goes across the garage. Pipes will be laid and backfilled, then recovered with concrete/self levelling concrete to replace the floor.