RSS editor - find and replace words of feed

Hi,

is there a RSS tool out there on the web where you can edit RSS feeds ? In the past I used dlvr.it to find and replace words or even skip feeds that contain a specific word but now they became premium and you have to pay for those services (quiet a lot in my opinion).

e.g.

I have a RSS of a Twitter feed and it goes like this : "CoolTwitterUser : Wow this is an amazing tweet !"
and I want it to be like this : "Wow this is an amazing tweet !"

kind regards