Hi For example: if you create a 4mm x 2mm size component, and you want to change it to 3mm x 1mm  so, you can click the track and drag the node to resize it, or delete the track and re-draw.  and you might be need to change the snap size to move your pad. and you can use hotkey M to measure the dimenssion.

If you want to resize a footprint in the PCB, you should ungroup it first, and then resize , after finish, you need to group it to be a package. the more information please refer at:[https://docs.easyeda.com/en/Schematic/Wiring-Tools/index.html#Group-Ungroup](https://docs.easyeda.com/en/Schematic/Wiring-Tools/index.html#Group-Ungroup)

Beware that if you have followed the recommended Design Flow in the Tutorial and you have created your PCB from a schematic and then you change the PCB package directly in the PCB, if you do "Import Changes..." from the PCB or "Update PCB..." from the schematic, then your manual changes in the PCB will be overwritten. For more on this please see (2) in: [https://easyeda\.com/andyfierman/Welcome\_to\_EasyEDA\-31e1288f882e49e582699b8eb7fe9b1f](https://easyeda.com/andyfierman/Welcome_to_EasyEDA-31e1288f882e49e582699b8eb7fe9b1f)