Change priority to simple high, medium, low

How do I change the Priority(from 0 … 100) field under Basic to a simple
drop down menu with the following options:

High
Medium
Low.

If this isn’t possible can I disable the preconfigured priority field and
create my own? If yes, how do I disable the priority field?

How do I change the Priority(from 0 … 100) field under Basic to a simple drop down menu with
the following options:

High
Medium
Low.

If this isn’t possible can I disable the preconfigured priority field and create my own? If
yes, how do I disable the priority field?

RT-Extension-PriorityAsString

-kevin