Sweet, Is it hard to do the over haulin my self? will it result in reataping, (even though my left side it almot completely scratched and falling apart

What i would have to do is,

Remove the sora shifter
Take out the cable fromt the sora shifter
install the ultegra shifter
put cable in ultegra shifter
test shifter
retape?
RIDE

IF im off please tell me, It is my first time doing something like this, thanks sydney and everyone.