Please read (2.3) in (2) in: [https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a](https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a)

OK, I did. Your article taught me that the place I was looking for is called "PCB lib editor", but it didn't say how to get there. Found out by a lot of clicking around that I had to click the "footprint preview window" on the right side in the library window. That was all I needed to know. I've got to say, if that was the only way to get there, that certainly wasn't very intuitive...

Sorry but this is why we ask people to read the Tutorial. Otherwise we have to explain everything everywhere. Shift+F > Search Libraries tool; Search for the part; Select the part: Then: Right-click > Edit.  Or: Edit button at the bottom of the window. 

Neither of the methods you describe (both of which I already tried) open the "PCB Lib Editor"; they open the "Schematic Lib Editor". This is what I clicked to open it:  This wouldn't (and shouldn't) need explanations or forum discussions if the command wasn't missing from the two intuitive places you just mentioned.

Select PCB libs on the Types bar.