Change the l-7 address physically

Your DMX splitter must support RDM.

Ok, 

What are the steps to change from the console ?

Which console are you using?  Normally, in the patch area, RDM can be enabled or disabled.  Since the fixture doesn't feed back what channel it is on the console, you'll either need to remember its address, or there is a discover/flash for you to see which fixture it is in the rig.  The RDM window will display the current info regarding the fixture.  Here is where you can adjust the personality and DMX address.

you should try over at the EOS forum. ;-) This is Cobalt.... 

community.etcconnect.com/.../eos-family

Thread Moved.

RDM needs to be enabled: in setup > system > outputs you can activate RDM per DMX port. if you're outputting through ETC gateways you have to activate it on the port itself as well as in shell > settings > network > RDM.

then go to patch, click Device List, RDM, activate Device Discovery. wait till it finds the correct L-7. select it by typing it's address. in the CIA you will now see all its properties. all those with a > in front you can change by RDM, the rest is read-only. click the start address and enter the new address.

Thank you Patrick for ur help ..