General:
* Lighten the burden
* Reduce the pressure
* Alleviate the stress
* Make things easier
* Simplify
* Take some weight off
* Provide relief
* Unburden
Specific to physical labor:
* Lift the weight
* Share the workload
* Reduce the strain
* Make things more manageable
Specific to emotional/mental load:
* Offer support
* Give a break
* Provide comfort
* Take the pressure off
The best choice will depend on the specific situation you are describing.