If you've got the space around it, and fairly deep soil with no
piping under it, you just stick a post near each corner, anchored with
cables, and hoist the thing. Use 4' long bits of #10 rebar as
stakes. If you haven't got the space for that, build a tripod
out of 10' galvanized pipe at each corner, and hoist the roof
on a pair of 16' 4x6s slung between them.