Code:
Option Explicit
Sub Multi_FindReplace()
'PURPOSE: Find & Replace a list of text/values throughout entire workbook
'SOURCE: www.TheSpreadsheetGuru.com/the-code-vault
Dim sht As Worksheet
Dim fndList As Variant
Dim rplcList As String
Dim x As Long
fndList = Array("$", "%", "&") '<-- list individual characters here
rplcList = "_"
'Loop through each item in Array lists
For x = LBound(fndList) To UBound(fndList)
'Loop through each worksheet in ActiveWorkbook
For Each sht In ActiveWorkbook.Worksheets
sht.Cells.Replace What:=fndList(x), Replacement:=rplcList, _
LookAt:=xlPart, SearchOrder:=xlByRows, MatchCase:=False, _
SearchFormat:=False, ReplaceFormat:=False
Next sht
Next x
End Sub