Add the VLANs required to the port, then set that port as a trunk port. VLAN 1 is enabled by default, so you could create a second VLAN, such as VLAN 2. The steps would look something like this:
conf t
vlan create 2 type port
vlan member add 2 48
vlan port 48 tagging tagall
The port on the switch that port 48 is connected to would need to be configured as a trunk port also. You then add ports on the second switch to VLAN 2. If you want ports 1-12 on the second switch to be in VLAN 2, and 48 is the uplink to switch 1, do this.
conf t
vlan create 2 type port
vlan member add 2 1-12,48
vlan configcontrol flexible
vlan port 48 tagging tagall
vlan port 1-12 pvid 2
vlan member remove 1 1-12