can someone help remove email account

[cslevine]

I set up the tilt to go over the house wifi and get my yahoo mail. Than I log onto yahoo with my laptop and my password is rejected, however it is still getting mail on the phone!! so yahoo thinks there are 2 of me I think. SO how do I delete the [pre installed yahoo account and reset through yahoo mobile? many thanks
plus how can i MAKE EXPLORER THE DEFAULT BROWSER, NOTHING COMES UP ON OPERA?? Many thanks