Humm, do you mean replacing www.youtube.com/watch?v=... by www.tubepen.com/watch?v=... ?
All browsers I have been used had an editable url field, this should be easy.
On desktop by double-clicking the word youtube it should select it an you can just write there.
All browsers I have been used had an editable url field, this should be easy. On desktop by double-clicking the word youtube it should select it an you can just write there.