Using QGIS 2.14.4 (Essen). I am trying to join an excel for data about species surveys which were conducted at different locations, by blocks of area which is a separate shapefile I have already. I am able to convert the excel into a CSV, add this with "No geometry" and then join this to the Block data layer by using shared Block IDs found in both tables, however, when joining data the attribute table columns are named after the originally joined excel file e.g."Anchor D_1"; "Anchor D_2" I found a solution here: Renaming attributes/fields in shapefile attribute table using QGIS?
However, I seem to be unable to rename any column which contains Integer data (see image). Any answers?