Options to provide tenants for early departure from lease?

[Justin S.]

Both tenants are joint and several liable.  One tenant request to leave for a new job.  Only options in lease to leave early are to payout full balance remaining on lease term or sublet pending landlord approval.  

The tenant wishes to payout "their" portion of rent until remainder of lease term.  Given the jointly and severally liable, there isn't an individual option for just "their" portion.  

First option is for both tenants to continue paying rent as they are doing through remainder of lease. 

Second option is to continue to search for sublet, mitigating monthly expense.

The third option is my question, can the two tenants write up an agreement, whereby I would witness and sign off on as well, that the tenant wishing to move pay remaining tenant 'their' portion of rent due for lease term?  There are benefits for each individual over other options.  The outgoing tenant would be removed from lease after move out date for their benefit.  Landlord would walk through with remaining tenant and all agree that remaining tenant takes over condition of premises.  The remaining tenant would then be solely liable for full balance due each month until lease ends with the outgoing tenant's monies in hand.  From landlord's benefit, the remaining tenant has shown to be very responsible and it is easier to contact someone not paying rent at property, should it occur, than someone that is in another city.  There is concern that moving tenant would decide not to pay at some point and thought is that it would be better to have money in hand of remaining tenant than not.  

Thoughts?