psu swapping out.

hey guys i want to upgrade my psu so i can get a better graphics card. found a steal on a modular psu so im going to get that one . when i built my pc after building it i payed someone to better mange my cables ( bad ik ) he used cable ties and all. im just wondering how much of a pain in a ass it will be to swap it other . cpu power cable is fairly tight

many thanks