Many times, you may be tempted to delete skills from your officer or leader. If you want to delete a skill but cannot, simply switch the leader's troop job to any infantry job (all units require melee, so that is one skill you cannot delete) and delete the non-pertinent skills from that leader.

Note that you will not be refunded the XP for deleted skills, so have a back-up save ready for times when your trigger finger slips.