I was starting a new project and when I was copying some webforms over to the new project I found loads of Meta:Resource tags like this:
To simply remove them all from your ASPX pages open the replace window (Ctrl+H).
Type this in the 'Find what' box:
Leave the 'Replace with' box empty.
Open up the find options at the bottom of the replace window en check the Use: Regular Expressions option.
And then go and replace/delete your meta resource tags.