I've just had a quick go - I had extra folds on sides too.
I did it again - do step 1, then step 2 AND keep this folded - do step 3 then open up and follow instructions from there. That worked for me and no extra folds on sides.
Hope this has helped and not made things worse.
The instructions are great Lynn - I think I was just a little nervouse and making more out of it than was actually there!!!