Hi

Goto the Menu: Edit/Go To/ select Special
In Special select Constants and keep Text checked. Uncheck the other 3.
Click OK

Now all your Text should be marked - make sure if you are uncertain!
You can now delete all Text by just pressing Delete.

The same can also be done manually by holding down Ctrl and click on every
thext you want to delete, and then press Delete.

If something goes wrong, hold down Ctrl and press Z to undo.

Ola