I am new to Chimera and am still getting to know the program. So far I have found the tutorials helpful, but they don't seem to have the answer to this very specific question. 

I want to know how I can overlay a protein structure and electron density map correctly. 

I am currently analyzing a published structure and would like to look at the the electron density map superimposed on the protein model. I was able to fetch the electron density map by using the 'open edsID:PDB_ID' command. However,  it doesn't seem like my structure and the electron density are overlaid correctly. This might be because I moved the structure a lot before calling in the electron density map. 

How can I have the electron density map overlaid to the structure correctly (like the author intended it to be).  
Any tips will be appreciated. 

Best, 

Jenaro