Hi Zeko,
You change it with the following command:
SW1(config)#spanning-tree vlan 1 priority 4096
Which sets the priority to 4096 for VLAN 1. This way, you can change it for each individual VLAN. You can also do this for a range:
SW1(config)#spanning-tree vlan 1-200 priority 4096
There’s also this command:
SW1(config)#spanning-tree vlan 1 root primary
You can use “primary” or “secondary”. Basically it’s a macro that checks for the current root bridge and then sets the priority of the switch to a value just above or below the current root bridge.
By default, the priority is 32768 for all VLANs so it’s the MAC address that defines which switch becomes the root bridge for all VLANs.
Hope this helps!
Rene