After a previous command you can always edit all your markups. Click ratecode link. Click View in Markup edit column.
Select the point you want to change and run the command
Chup(+15%(0%))
Or
Chup(+15%) – this will change markup only and will leave commission at the same level
or
Chup(+50)
After you finish editing hotel markup you have to publish all the changes – link on the bottom of the page