With the new 4 Player skirmish map included with the Hoth Expansion, how does one deploy the AT-ST and the Tank? Deploy as normal and side shuffle through the peaways? or how does that work? Thanks everyone.

You use regular skirmish deployment rules, then regular large figure movement rules.

There is no facing in the game, so there is no sideways as such.

I like picturing the AT-ST side stepping through Corridors. Makes me think of the Ewok log scene in ROTJ.

But essentially yes there is no real facing. A massive figure has to obey the rules for the Massive Keyword and for Large bases so it takes a movement point to rotate 90 degrees and then it can shuffle through that corridor.