How to Replace the values Using Salesforce Formula field

We can easyily remove the last character from a string by using the SUBSTITUTE() in the Formula.
For Instance, If value__c is a string (TheBlogReaders.com) and we can replace from .com to .net using following formula

Formula:
SUBSTITUTE(value__c, ‘.com’, ‘.net’)

Result: TheBlogReaders.net

SYNTAX:
SUBSTITUTE(text, old_text, new_text)
Substitutes new_text for old_text in a text string. Use SUBSTITUTE when you want to replace specific text in a text string