Canot get the back off my Indiglo watch to change the battery

There is different proccedure for different watch to take out the back. Following are some of the proccedure to open the backcover of the watches:-
1. Some plastic watch have four screw in the back, you just have to unscrew the screws and take out the back.

2. Some of the watch have press back technology, which enables the watch to be water resistant and thus, the backcover of these watches are pressed very tight. You just need a back opener, and at the back if this back opener has to placed between the case and backcover and has to be tilted and backcover can be opened.
(Backopener is a tool which is like thick & hard blade with sharp edges like knife but not very sharp; these edges can get easily between the gap of backcover and case. - this tool can be obtained from any watch tools store easily)

A ******* Sledge Hammer !