Just split the rental income between the 2 properties based on each properties actual rental income (as if you received 2 separate 1099-MISCs). You may need to contact your property manager to get the information about each property's actual rental income. 

You can still report the separate rental income amounts under each rental property as income reported on a 1099-MISC since the combined income total of the 2 properties will equal the copy of the 1099-MISC received by the IRS. Just make sure that the total being reported for each property equals the total reported on your 1099-MISC.