Is it open for PSU upgrade and motherboard extraction

Is it open for PSU upgrade and motherboard extraction

i have this sff HP, HP Elite Desk 800 G1 pc and i want to replace its stock power supply from 350 watts to a higher because ive heard that if i plug in a single fan GPU onto it, the psu will fail. besides, i am also planning to extract its MoBo and put it into a bigger case for more room. is these possible??