2.5i 6mt front differential oil seal replacement question

2014 2.5i 6mt here. I busted my front differential oil seal while replacing my clutch last month and am planning on changing the seal this weekend. Can I remove the seal with a seal removal tool and tap the new one in place or do I need to remove the sun dial and do it from the inside? Subaru part person said I can use the seal removal tool but most of the videos I've found do it the other way... Planning on going back to Subaru tomorrow to pick up an O ring just in case.