You can record a macro doing a Find & Replace. Then you can replace the search/replace strings with Input Boxes for your users. Here's an example:
<font face=Calibri><SPAN style="color:#00007F">Sub</SPAN> FindandReplace()<br> <SPAN style="color:#007F00">' Find a string in every sheet and replace it with something else</SPAN><br> <SPAN style="color:#00007F">Dim</SPAN> x <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">String</SPAN>, y <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">String</SPAN><br> <br> x = InputBox("Replace What?", "Replace What")<br> y = InputBox("Replace With?", "Replace With")<br> <br> <SPAN style="color:#00007F">For</SPAN> <SPAN style="color:#00007F">Each</SPAN> ws <SPAN style="color:#00007F">In</SPAN> ActiveWorkbook.Worksheets<br> <SPAN style="color:#00007F">On</SPAN> <SPAN style="color:#00007F">Error</SPAN> <SPAN style="color:#00007F">Resume</SPAN> <SPAN style="color:#00007F">Next</SPAN><br> ws.Cells.Replace what:=x, replacement:=y<br> <SPAN style="color:#00007F">Next</SPAN> ws<br> <br> <br><SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN></FONT>