Two zimablade with same mac address 0e:48:76:7a:e9:e9

Hello, I have two zimablade on the same network but they have the same mac address : 0e:48:76:7a:e9:e9.
What method do you recommend to change them permanently?
Can I use 0e:48:76:7a:e9:ea for one of the two?

Thank you in advance por your response.