You need a UserBase account before you can be added to the Translator group, register or log in here. The workflow for translators is described in Translate a Page.
Be aware that your contribution will be governed by the Gnu Free Document License and Creative Commons License, see KDE UserBase:Copyrights for details.
Information
To request a Translator account, please post here:
Your UserBase username,
and the language(s) you will work with.
It is helpful if you tell us whether you intend to use off-line translation. Off-line translation means using other tools like Lokalize and uploading ready translations here. This is for planning only, and you can change your mind. When your account is added, please read Tasks_and_Tools and the relevant linked pages. You are not confined to translating the language you registered as long as your grasp of the language is sufficient, and you do not need any additional registration.