How can I find and replace all occurrencies of a character in vim? -

i have strange character in text, how can find of occurrences , replace character?

i know if need same thing word can use * , :%s//replacement/g replace occurrences,

is there similar characters?

1. yank character register (a in case): "ayl

2. start substitute command :%s/

3. use <c-r> a paste register command line.

4. finish command , execute: :%s/<char>/<new-char>/g