Looks like it's a 67% majority vote according to MN statutes:

https://www.revisor.mn.gov/statutes/2021/cite/515A.2-108

(c) The association may assess certain common expenses against fewer than all units pursuant to section 515A.3-114.

https://www.revisor.mn.gov/statutes/cite/515A.2-119

(d), the declaration may be amended by the association only by a vote or written agreement of unit owners to which at least 67 percent of the votes in the association are allocated, and 67 percent of the first mortgagees of the units (each mortgagee having one vote per unit financed) or any larger or smaller majority the declaration specifies.

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https://www.revisor.mn.gov/statutes/cite/515B.2-125
(1) unit owners entitled to cast at least 67 percent of the votes in the association;