Sorry but the datasheet for this part is useless. 1. It does not specify the pin diameters and 2. the dimensions of the 20VA part are not specified at all. In fact the pin diameters for up to the 12VA part are specified on the RS product page: https://uk.rs-online.com/web/p/pcb-transformers/0504684/ but the pin diameters for the 20VA part are still not specified there either. If you do not already have a part that you can measure then I suggest you contact RS (http://asia.electrocomponents.com/web/) for this information or choose a different, properly specifed component. * Once you have the dimensions then you can create your own PCB footprint: https://easyeda.com/Doc/Tutorial/PCBLib.htm#Creating-The-PCB-Libs * You can also create your own Schematic Symbol: https://easyeda.com/Doc/Tutorial/SchematicLibs.htm#Creating-the-Schematic-Libs