How Can I Combine/Merge Multiple Weight File at Yolov5

Question

I have 3 weight file. Let's say....

1. face.pt
2. hands.pt
3. legs.pt

Right now, I run run every single weight file and detect particular section. But I want to detect those three section In one run.

I want to detect Face,hand,legs in single screen.

I want this.... say I command python detect.py and its detect face,hands,legs in every person.

For this I need to combine weight file. Right?

How can I do this? I am using Yolov5. Or any alternative solution?