The full process is described on the United Church of Canada website.
Go to http://www.united-church.ca/files/handbooks/can210.pdf

1. A person who has been a member of the United Church of Canada for at least two years and is an active member of a United Church congregation experiences a call to ministry, or a specific call to diaconal ministry.
2. That person formally requests the congregation to set up a discernment committee for them, using forms provided on the United Church of Canada website at: http://www.unitedchurch-ca/files/forms/dis201.pdf
3. If the Church Board/Council decides to enter in to discernment with the individual, it appoints two members of the congregation to the Discernment Committee and forwards the request to the Presbytery. The Education and Students (E and S) Committee appoints one or two members of the Presbytery to the Committee.
4. Once established, the Discernment Committee meets with the inquirer at least six times over the course of twelve months. Part of the work of this committee is to help clarify, for the person and for the committee, the form of ministry most suitable for the inquirer: diaconal, ordained, designated lay ministry, congregation designated lay ministry, or lay leadership in their congregation. When complete, their report is sent to the congregation.
5. If the congregation agrees with the recommendation that the person should proceed toward candidacy, the documentation is sent to the E and S Committee who arrange for an interview with the Conference Interview Board. If the congregation does not agree, that message is conveyed to the E and S Committee.
6. Following the interview , the E and S Committee will meet with the inquirer again. If the recommendation was for candidacy, the E and S Committee will proceed to the next step in the process. If the recommendation was otherwise, the E and S Committee may accept this recommendation and inform the inquirer that the process has stopped here. Or – the E and S Committee may ask for another interview with CIB, after which the E and S Committee will meet again with the inquirer.
7. When the E and S Committee has made a decision to recommend an inquirer, the request then goes to Presbytery. Once approved by Presbytery, the inquirer is officially a candidate for a specified form of ministry.
8. The candidate completes the educational requirements for ministry through a recognized United Church educational institution. Candidates are interviewed annually by the Education and Students Committee. When their studies are complete, candidates are interviewed by the Conference Education and Students Committee. They will be settled in a ministry position prior to commissioning, which takes place at the Conference meeting.