You have to use the 1st Gen Editor to change personal skills but Pavise is one of the various skills that you can't give as a personal skill to fix this you have to use the Character Skill Table Editor and change the great shield entry to your number of choice I changed it to 20 so if I want to give Sigurd another skill from the Skills1 entry e.g. Pursuit, Continue Charm, etc. You have to use a calculator to sum the value of the skills in your case you want charm too so it will be 10+20=30 if you choose 20 as the value for pavise.
