In the workload space transfering work from one employee to another can be done in the matter of seconds. To transfer work:
Navigate to to the workload space
Click on the member's name to expand the row to see work plans
Click on work plan you want to transfer
Use the name drop down to reassign to the new member
Note: Add Member box will appear if the member is not currently a member of the project. You will need to click add to continue
Click done on the work plan
The work plan will show on the new member