Hollow Sirene Issues

If someone has completed this quest and could let me know how to get into the scientists tomb, that would be great!

 

There should be a button on one of the graves relatively close to the entrance, press it and follow the particles, they should lead to a another grave, press the button hidden there and follow the particles again, this time I think that they go into the cave area and down the path, press the button there and follow them to the tombs entrance, it should open(I'm not sure about the graves positions though, just follow the particles and press the buttons). There will then be a puzzle in there where you have to walk on the pressure plates with emerald block(it changes each time) quick enough.