Electrical – Altium : Default Visible Parameters in Sch library

You can try to do pad-over-pad but this will probably generate a Design Rule Check (DRC) error.

You should be aware of Altium's "electrical grid", if not look up in the knowledge center. I believe the shortcut is shift+e. The electrical grid causes the cursor to "snap" to electrical connections.

What I would do is delete all but one pad for each footprint. Then I would grab the part by the pad that matches the one not deleted; Altium should "snap" to grabbing the part by the center of the pad the cursor is over. Drag the component overtop of the undeleted pad and the component should "snap" into place. Let go, and you'll probably be meeted with the ugly green DRC error highlighting. Click the undeleted pad, Altium will list several things under the cursor, select the pad, and delete it.

Another way to move the component if you happen to know precisely how much distance you need to move can be found under Edit -> Move -> Move Selection by X,Y... In fact, I have set up a shortcut for this action.

BTW, you said you were new, so forgive me for asking...but do you have a schematic for your design? I've never personally went "this direction", importing step files to get component positions, it was always the other way around with me exporting my PCBs for the SolidWorks guy, and then if he needs me to move a connector I Move Selection by X,Y... to match whatever he asks for.

• Create a folder and name it "Altium Libraries" (or any other name you prefer). This folder will contain all your libraries.

• Within that folder create several subfolders with names like:
  "Resistors" (for all resistors you will add to the resistors library),
  "Capacitors" (for all capacitors you will add to the capacitors library),
  "Atmel" (for all parts from Atmel you will add to the this library),
  "Samtec" (for all parts from Samtec you will add to the this library),
  ...
  

• with Altium open and running, click on file tab (left bottom corner of work space, find "Blank Project (library Package)" and click on it. A new Library Project will be created.
• in Projects tab (next to the Files tab you clicked before) right click on the new library project and add to the project a new PCB library and a new Schematic library.
• save this project and its two added files in the "Resistors sub-folder" with proper names (such as Resistor.LibPkg, Resistors.SchLib, Resistors.PcbLib"
• now add all Resistors Schematic symbols (each with its P/N as Design Item ID), Then Footprint with name such as "0402-0.4mm", "1206-1.2mm", ... and add to each symbol the correct footprint.
• right click on "Resistors.LibPkg" within the Projects Area (left column of your screen) and compile it as integrated library. Don't forget to address compile errors and warnings.
• Do these steps for all other libraries. You are going to have several compiled libraries
• Now in your real design project, try to find "Libraries tab" and click on "Libraries..." button and install the integrated libraries (if you can't find this tab go to the View menu/Desktop Layout/Default.)
• This way you always have your libraries for all projects. Whenever you have a new component, simply open the relevant library project, add the component and its footprint, and recompile.