How do I get this off painlessly?

Hayley • ~IT'S A GIRL!! 💕baby # 2 due May/June 2019~ 💙William Jack 17-08-17 💙

My son got his 4 month shots 2 days ago and the tape they used hasn't come off yet. He's been bathed but I don't want to rub at it too much in case it hurts him. Any ideas? Update: thanks for the suggestions, tried baby oil which worked a little but didn't get it all. Don't have any coconut oil so I think I'll just give the baby oil another go or try the alcohol wipe next bath and hope it gets the rest. Thanks!