Hi Luis
If you are having schedule to upgrade the both instance, you can follow the SAP Note as mentioned by Benjamin. and you have to copy the Kernel file to "\\sysdec01\SAPMNT\SID\SYS\exe\UN\NTADM64 for windows " (Not on/sapmnt /MAB/exe&/sapmng/MCD/exe ) you can follow the kernel upgrade steps from the SCN link
http://scn.sap.com/thread/3157702 (For Unix)
BR
SS