Você também pode conseguir isso com um script simples escrito em python:
replace.py
f = open("index.html",'r') # open file with read permissions
filedata = f.read() # read contents
f.close() # closes file
filedata = filedata.replace("1111", "1234") # replace 1111 with 1234
filedata = filedata.replace("2222", "2345") # you can add as many replace rules as u need
f = open("index.html",'w') # open the same (or another) file with write permissions
f.write(filedata) # update it replacing the previous strings
f.close() # closes the file
execute:
python replace.py