I've walked around it i cannot find a path up.

It depends on where you are starting from, doesn't it? I believe Istvaal (some town like that) is at the base.

You could also get Clairvoyance to help out.

Ivarstead in The Rift hold is the launch point for the path up.

I need help here too. I've followed the stepped path all the way up the mountainside but at the highest point it starts to wind its way down on the other side. The peak is still way up there but there's no discernible route, just impassable rocks and snow.

Edit: turns out even though the path goes down again you just have to keep following it and eventually you'll get there.

PS frost troll = deathclaw. Make sure you got some potions at the ready!