how to merge 3 assets after run depreciation

Hi all,

I have this case with the customer,

they have 3 assets related to each other and already have depreciation on. now they need to merge them all into one asset and close the other two assets.

the asset is a machine. but when they received it, they created it as 3 individual assets  (monitor, control system ....)

now they need to merge two of them to the third one.

which function could help on that. and how to handle this case?

thanks.