How to change the 8021p value inside the packet/frame?

How to change the 8021p value inside the packet/frame?

Create one vlan, for example vlan 2 in the eth port, when the vlan interface sends out packets/frames, vlan id(8100 0002) will be included, the problem is how to revise the prio value inside the vlan id(the default value is 0).

Any suggestion is welcome!