These mods change the actual birds and pigs. Common examples include:
For those seeking the untouched, original 2011 experience, the Internet Archive hosts various versions of the game’s original installation files. angry birds rio sprites changed download
Locate a trusted community archive or modding forum (such as the Angry Birds Modding Community or GameBanana) to download the "Angry Birds Rio 2011 Sprite Pack." These mods change the actual birds and pigs