First two things you need is the Gravity Spikes and all four upgraded bows.
When you have all 4 bows upgraded. Plant your gravity spikes right by the bell towers clocks mechanics by using L2
Go to the control room of the bell tower and find the control panel. There will be a panel and lever. You need to hold square to start the clock which is frozen on 1:15.
When you pull the lever the first time you it will start the clock.
Have a player stay outside and tell you right before it's at 9:35. You need to stop the clock exactly on that time.
If done correctly you will here thunder and see lightning strike the bell towers antenna.
Make your way to the Pyramid room and there should be a floating orb when anti gravity is off.
When anti gravity turns on, you need find the smaller circles and jump on them. One will teleport you.
Go to the right of the teleporter when teleported and hold square by the table which picks up the Plunger.