Sounds like you might be a novice at removing cylinder heads. That's OK. We all have to start somewhere. This is a good engine to start with.
It's a single cylinder pushrod engine. You won't be disturbing the camshaft timing so you can remove the head with the crankshaft in any position.
However, I'd suggest that you put the piston as close to TDC as you can before you start, simply to stop any debris falling into the cylinder. Before fitting the new gasket, you'll have to scrape the gasket mating faces clear of any old bits of busted gasket, carbon, dirt etc. which can drop into the cylinder. It's a lot easier to retrieve any crap if the piston is at the top of the bore. A nozzle on a vacuum cleaner hose will get rid of any small bits before you put the head back on.
I'm not familiar with the 20 Mojave engine in detail, but looking at photos, it appears that the head and cylinder are both held on by head studs that go down into the crankcase. In that case, the cylinder will be free to lift up when you remove the head stud nuts. But try not to lift or jiggle the cylinder as you remove the head. If that does happen, chances are you can re-seat the cylinder and get away with it. But if the base gasket tears, and any pieces of gasket are displaced, you'll have to lift the cylinder right off and replace the base gasket too. It's all do-able, but you're better off not disturbing the piston rings if you don't have to.