HTC Desire HD :: Removing Default Apps/ringtones?

I hate things like facebook and twitter however my desire hd sim free came with several apps installed i.e default ones.I have downloaded god knows how many file managers that let you uninstall apps however not yet found one that will let you uninstall the default ones. My second problem is that i am trying to delete the ringtones on the internal memory and also add my own to the list as it appears that you can only assign individualy ring tones to contacts that are the default tones is this correct? I can locate the files however the phone will not let me delete them add to them or modify them what so ever. Managed to now add ringtones to the default set so i can now use my own for individual contacts, just not managed to delete the default ones. I have just found something even more annoying the phone wont let me use my own text message alert i have stored on my phone anyone found a ay round this rather than using one from the net that the phone will let you download?i have also tried doing it via plugging it into my pc however it wont let you view the system files even by changing option to view system files under windows it will only allow viewing of the sd card.