I found myself a solution. Here's what I did.
Find:
gecc.ExcelToGrid(ws, Me.GridControl1.Model)
Replace with:
Me.GridControl1.Model.RowCount = 0 ' Clear the whole grid
gecc.ExcelToGrid(ws, Me.GridControl1.Model)
Me.GridControl1.Model.RowCount = Me.GridControl1.Model.RowCount - 1 ' We get an empty row at the end, probably because of the "DeleteRow(1)"-call earlier. This will remove the empty row since it's at the bottom.