Get it up in the air and have a good look at the reverse mechanism somewhere there will be plunger switch.
If I have to tell you any more then you should leave it hooked up :laughing:
As for turning, the problem is the lack of a diff so one of the drive wheels has to slip in order to do tight turns.
the solution is to mow backwards around the tight spots.
It will turn a lot tighter in reverse that t will forward so of course you will need to disable that less than useless reverse cut out.
Just make sure you watch where you are reversing and make sure there are no live power cables laying on the grass before you start to cut.
I have lots of old mowers from the 60's & 70's all with fixed rear axels & I can mow faster in reverse than most modern tractors can forward, it is just a matter of getting used to the tiller action.