You only need to find the bold ones, not all of them and you only need to replace the formatting, not the underlying text:
Code:
Sub ScratchMacro()
Dim oRng As Range
Set oRng = ActiveDocument.Range
With oRng.Find
.Text = "[" & Chr(13) & ".;,]"
.MatchWildcards = True
.Font.Bold = True
.Replacement.Font.Bold = False
.Execute Replace:=wdReplaceAll
End With
lbl_Exit:
Exit Sub
End Sub