Help Finn walk

Finn is calm and always wants cuddles. He will always ask you politely for affection. He was never able to walk correctly. Both of his back legs have patellar luxation grade 4, meaning his knee caps were never attached, causing muscle loss. His surgery is over 10k and we can only do one leg at a time. Each leg will take 8 weeks to heal. , Finn will live longer and have a better quality of life. He will be a completely different dog, meaning he will run, jump, hike and play. Please help Finn.

https://youtube.com/shorts/WS7iDEYDd2U?feature=shared