How to use vim to quickly convert text to upper or lower case

Vim has a lot of utilities built in for processing text here is one for conversion of case on plain text.

First Visual select the text you want to bulk change the case of.

For lower case to UPPERCASE

Press Shift + U or what is known as a capital U.

For UPPERCASE to lowercase

Press u or lower case ‘u’

The selected character are transformed to the case of your choosing.