Yup not too hard, just awkward keeping the belt on the RH cams without them springing round.

As soon as you remove the tensioner pulley allows some slack on the belt the right hand inlet and exhaust pulleys will spin round. Sadly Subaru never thought of equipping this car with locking holes on the pulleys/heads, which is nuts on a 4-cam engine

Bulldog clips are your friend. And half a tooth out like B13BATs is fine.

Also use a shaving mirror (or similar) to double check timin marks.