Open the Pluto Admin Website. At the right under the "Advanced" menu there will be item "sqlCVS", with various subitems. I recommend you to do the "diff" first to inspect changes, and then do the "checkin".
Note-1: since you are editing/adding device templates, you should select only tables under "dce" category
Note-2: without providing login/password the changes will be commited as 'anonymous' and will not go into mainstream w/o admins approval. As far as I know, you can use your plutohome.com site login/password for doing into sqlCVS. I am not 100% sure, so please post here if you will experience any problems.