Unmapping LUN from igroup urgent help needed

Hello Netapp engineers , 

I an doing a DR test , in the process I did - 

snapmirror break -destination-path drfcpt1:CC_hqcvcp01_SP_311_Copy_568_hqfcpt1_hq_t0_ss01_Mirror

next, created an igroup & mapped the lun to the igroup

lun map    -vserver drfcpt1 -lun /vol/CC_hqcvcp01_SP_311_Copy_568_hqfcpt1_hq_t0_ss01_Mirror/hq_t0_ss01 -igroup DR_IGROUP -lun-id 60

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Now for the post clean up test - 

1)

lun offline -vserver drfcpt1 -lunf /vol/CC_hqcvcp01_SP_311_Copy_568_hqfcpt1_hq_t0_ss01_Mirror/hq_t0_ss01

2)lun unmap -vserver drfcpt1 -path /vol/CC_hqcvcp01_SP_311_Copy_568_hqfcpt1_hq_t0_ss01_Mirror/hq_t0_ss01 -igroup DR_IGROUP

3)

snapmirror resync -destination-path CC_hqcvcp01_SP_311_Copy_568_hqfcpt1_hq_t0_ss01_Mirror

Question - 

1)Do i have to necessarily put  the lun offline before unmapping ? If yes , I do I have to put it online again before running step 3 . i.e when running  snapmirror resync. Or the step mentioned above is good . 

2)Also, I do not see the  flag to unmap the luns using lun_id in step to 2 . For example , I used lun id 60 to map the luns  , do I have to specifically mention the  -lun-id when unmounting 

Thanks,