In order to answer this, we first need to understand how assimilation and accommodation differ from one another. These are two very different approaches to dealing with the presence of a minority in a society. In assimilation, the minority essentially becomes like the majority. The minority throws off those aspects of its culture that make it very different from the majority and becomes a part of the majority. This is the “melting pot” model that has long been the goal for many in the United States. In accommodation, the majority essentially has to accept the ways in which the minority is different. In this reaction, the minority is not asked to change its ways. Clearly, non-Muslims would have to act in very different ways to help foster these very different outcomes.
To foster accommodation, non-Muslims would need to be respectful of Muslim beliefs. For example, they would need to accept the idea that many Muslim women will veil themselves to some degree. If they have Muslim employees or students, they will need to make it possible for those Muslims to engage in prayer at various times in the day. Non-Muslims who run schools would have to make halal meals available to their Muslim students. All of these things would allow Muslims to feel comfortable in society without having to change their beliefs or actions.
Fostering assimilation would be harder because it is essentially up to the Muslims to change their ways. Non-Muslims could act in ways that would try to force assimilation. They could bar women who are veiled from entering their places of business. They could have dress codes that barred men from wearing beards. They could refuse to help Muslims cope with the need to fast during the daylight hours of Ramadan. These things would not really help Muslims at all. Instead, they would work to coerce Muslims to assimilate by making it hard for them to maintain their traditional ways.