You can do most of the steps for both on solo but as stated Rictofen doesnt get the Golden Rod, but you can still do the first half and get the plates onto the teleporter and onto the platforms beside the computer aswell as adding the pipe but you cannot go any further, but it is a good strat to do all the following steps on multiplayer,
1. Samantha Says
2. Hack the wall pads
3. hack the wall computers
4. press all 4 buttons within 2-4 secs
5. while your waiting for "Pi" to breach tunnel 6 (if your not lucky enough for it to be done already)
6. go to earth and "recover" the plates and QED them into place,
7.find the pipe (found under hacking device tables or at the top the 2nd floor lab stairs) and connect it to the computer,
8. add the Vrill Generator (Golden Rod)
9. mash X until the computer stays green
10. By now tunnel 6 should be breached (if it hasnt by round 10 I would advise a restart because beyond 10 maybe even beyond 7 it can be a real pain to continue)
11. follow the egg to the pyramid, once its in place fill up the tube (25 Zombs)
12. *Now here's the smart part* you will recieve 90sec Death Machines, but instead of going to Area 51 or Blazing through the round you should insert the powered up Vrill Generator and fill nearly all of the 4 tubes by using your Death Machines.
13. Continue the rest of the easter egg with somewhat less difficulty
EDIT: I am unsure if this has been posted and to any and all Flamers & Trolls I cba looking for a thread that had this tip in it because its 5am and I felt this was an appropriate place for it instead of another EE Tut Thread