I just replaced my ultegra hydraulic pads I presume yours will be the same Shimano code is lo3 the one you have are probably lo2a which the above replaces . These are the finned resin pads .
Just be careful with the pad restraining bolt mine was seized and made of cheese otherwise simple job YouTube is full of videos . You can use a different brand like Clarke's which are massively cheaper £5 at set
Correct bolt
Pads will fit but are sintered (metal) lo4a they will wear the rotor quicker . The one I used are resin lo3a
Off my two bolts 1 came out easy the other was completely seized you will soon know when you go to undo be careful applying force as I rounded off the head without much effort