I can’t imagine any disruptors getting anywhere near the actual swearing in ceremony. It’s normally held on the W side of the Capitol Building, up a few flights of stairs that for the ceremony is filled with VIPs, military, bands and choruses .... not to mention, snipers on every building and in most trees between the Capitol and the White House. And we can’t leave out the tens of thousands of Trump supporters who will be filling the Mall right below the Capitol. Any disruptor showing up there would be readily dispatched.
You will have to have a photo ID and been cleared by SS to get within the parameters of the event. The disruptions will be in other parts of town.
That is how it is supposed to be done; don’t forget O & Company are in charge of security. They do not want Trump sworn in so anything is possible this time.
As with Congressional committee hearings and State of the Union addresses, any disruptors at the Inauguration would probably be provided all the passes and credentials they need by their Democrat-member-of-Congress enablers.