The situation as I'm aware is that the Surinamese had a large amount of people who wanted independence, but also a large amount of people who were in support of continuing their relation with the Netherlands like Aruba and other Dutch Caribbean islands had. New Guinea had a lot of people who didn't like the Dutch and would like to unify with the eastern half of the island, but on the other hand were absolutely terrified of Indonesia which wanted to annex them. Presumably, the Dutch could negotiate with them for protection, and indeed, the Dutch had to protect them from the Indonesians multiple times in the 50s.
What you need is the Dutch to more firmly commit to keeping these places within the "Dutch colonial empire", call it the "Kingdom of the Netherlands" as it is now instead. I don't see how the Netherlands could have done worse of a job in Suriname as what happened in Suriname in the 1980s given the violence and drug trafficking. New Guinea might be harder, but it probably wouldn't be too hard to "win the hearts and minds" of New Guineans to view the Dutch as a necessary evil against the Indonesians. The problem here is that the Dutch will need the spend the money for military forces in these regions to repel the most radical independence movements as well as in the case of New Guinea the Indonesians, and I'm sure both New Guinea and Suriname will demand plenty of funds from the central government to help develop themselves and thus be a drag on the Dutch economy. This is a problem, but it's manageable if the right people are in power. I think New Guinea will eventually have to be cut loose, although after a strong agreement with Indonesia exists, but Suriname is probably capable of being part of the Dutch empire the way the Dutch Caribbean is now. I think the Dutch can do better than OTL Suriname, with the massive amounts of emigrants and the drug conflicts and massive murder rate that occurred there.