Thanks to Jon H., I can now do find and replace in files on Linux machines from the command line. Its pretty simple, but I had never bothered to figure it out.
Here are two examples. The first is for just one file, the meat and potatoes are in the second example, which does a find and replace in all PHP files.
sed -i -e "s/TOREPLACE/REPLACEMENT/g" temp.txt;
sed -i -e "s/TOREPLACE/REPLACEMENT/g" `find -name '*.php'`;
Super helpful.