Take the following steps:
- Go to www.ultimate-guitar.com and click "+Publish tab" button
- Write the tab or upload your GP/Power Tab file.
- Then just click "Save as personal" button.
- You'll find your Personal tab in "My Tabs" section.
Note: if you don't have an Ultimate Guitar account, it's worth registering one before you start creating the tab. This way you won't lose your Personal tabs.