Great question - I would love to hear about this, too.
Great question. Like residential tenants, commercial tenants don't want a big increase in their rent. If you elect to convert gross leases to NNN leases, you'll most likely need to reduce the rate so it is equivalent (or maybe slightly above) the amount the tenants currently pay.
Before you walk down this road, make sure the commercial units are separately metered. Some multi-unit commercial buildings are tough to lease as NNN because the utilities are on one meter.