1、Enter the  directory "MP_551_EXPRESS_B396" 
2、Execute “setup.exe” as   administrator
3、Enter the  directory "ARM_LE_GCC3_eCLR_forMP5.50_Delivery_20160726" 
4、Execute “ARM_LE_GCC3_eCLR_forMP5.50_Delivery_20160726.exe”  as   administrator
5、COPY these four files 
"firmwarelib\SystemARM_LE_GCC3.INI" ,
"firmwarelib\System\eCLRDeviceProfiles.xml" ,
"firmwarelib\System\IO_DRIVER_LIB.dll" ,
"firmwarelib\SystemSHM_LIB.dll" 
TO the following directory
X:\XXX\PHOENIX CONTACT Software\MULTIPROG 5.51 Express Build 396\plc\eCLR\ARM_LE_GCC3\

6、COPY these four files 
"\firmwarelib\FB_FU_LIB\FB_FU_LIB.DLL" 
 "\firmwarelib\FB_FU_LIB\FB_FU_LIB.FWL" 
"\firmwarelib\FB_FU_LIB\FB_FU_LIB.POU" 
"\firmwarelib\FB_FU_LIB\tmp.sto" 
TO the following directory
C:\ProgramData\PHOENIX CONTACT Software\MULTIPROG Express\5_50_10151\plc\FW_LIB\FB_FU_LIB
Note! This folder is hidden by default. You need to modify the folder option to display it,Or directly enter the directory in the folder navigation bar.