Have them do it. I’ve never had any issues with McIntosh customer support or their service. They’ve always been stellar and one of the reasons I purchase their products. They are trying to maintain the integrity of their products and avoid having to fix issues (and they will) caused by improperly installed firmware.
Mcintosh customer support
Requested Firmware update from Mcintosh for my ageing but still good sounding D150 Dac Mcintosh customer support virtually refused to supply Firmware v 1.02 with me . their answer was,,
( Unfortunately, company policy prohibits me from sending out firmware updates. We used to distribute them openly but they ended up on forums and were installed into incorrect units causing a massive influx in service repairs. At that point the company instituted the policy to no longer distribute them.)
it is so sad that Audio Giant like McIntosh do not care about their customers.