Importing .STP assembly file as single part

[MB_10357724]

is there any easy way to import .stp assembly file into part as single file ? pls assist.

I tried converting assembly as Parasolid model and imported into the part. but it was unsuccessful.  

[StephenW · Accepted solution]

https://community.ptc.com/t5/3D-Part-Assembly-Design/Import-assembly-steps-as-a-single-part/m-p/579717