Can you point me in the direction of what youtube videos you used please?.I too atempted this repair with a screen purchased from ebay for £13.39 (TDO WVGA0633F00039 TDO WVGA0633F00045).
I followed the advice on this thread and a couple of youtube videos and it all went straightforward. I have fixed iphone screens in the past and would say this was far easier. There was an amount of tear down to get to the screen but all went okay and fully working again.
Remember to lay the replacement screen directly over the failed one. Do not try to remove the failed screen.
I would say to have a go yourself and save the couple of hundred quid it costs to have this done by 3rd party companies that advertise on here.