For the merge itself, you just have to be patient and wait 30 days; if the profile manager doesn't approve, postpone, or reject the merge during that time, it's assumed that the profile manager doesn't object to the merge, and you'll be able to complete it.
For making other changes: On the bottom right of the profile page, there's a set of links that includes "open profile request" on certain records; you can use that to request that the profiles be opened. You can also email the WikiTree info email address to request it.