Yes, a static maneuver. I think the only modifier is Disarm skill unless you want to apply situational modifiers.
The MAC version is different. In the MAC, the attacker makes a static maneuver with their Disarm bonus, subtracting the defender's total OB (before subtracting parry and special attacks). If it succeeds, the weapon is dropped. If it succeeds really well, the GM "may decide to let the player decide where the disarmed weapon will go."
This is different than the RMSR/SoHK version, where the attacker makes a static maneuver with their disarm bonus, not modified for OB. If successful, the defender makes a RR using their number of ranks in the weapon skill as their level and the attacker's number of ranks in Disarm as the attacker level.
The RMSR/SoHK version ignores defender stat bonuses, profession bonuses, etc. The MAC version is more streamlined and also takes these into account.
MAC also makes some other changes. They do not list the B critical for a failed Disarm (Unarmed), which makes sense to me (you're probably going to get hit anyway, an automatic critical seems inappropriate unless you fail very badly). They limit your Disarm skill to no higher than your weapon (or martial arts) OB, but your available OB is reduced by the same amount you put into Disarm. E.g. if you have 100 OB, and 30 Disarm, that leaves you 70 OB to split between attack and parry.