How do you open an estate and get a tax ID number when the deceased passed 2 years ago and there was no need for one at that time?

It's not a problem to open an estate and obtain a tax i.d. number 2 years after death. It is relatively common for issues to arise later that were not anticipated. However, I might question the information you are getting from the insurance company.  Insurance proceeds are not generally probate assets, unless the estate itself, and not a person, is named as the beneficiary.  If that's not the case then you might be able to use the Colorado Small Estate Affidavit, or an affidavit provided by the insurance company, to collect the proceeds. Not all state laws are the same, and insurance companies and other institutions often give out incorrect information about whether a probate is needed.