You can apply for Argos positions online or directly from their stores in the UK. Grab an application form and fill it nicely and then return it to the store where you want to work.
They will call you to arrange an interview as soon as they think you are good enough to work with them.
Christmas hiring process is just the same as for any other roles.
you will most likely to have Group Interview so be prepared for that kind of interviews. You would either try to solve a puzzle or design something from a poster then they would start with one to one interviews with the candidates.
Here are some of the most asked one to one interview questions and possible answers:
Tell me about yourself
Why should we hire you?
Why do you want this job?
What is your greatest strength?
What is your greatest weakness?
What are your salary expectations?
What motivates you?
Give some examples of teamwork
Describe a difficult work situation project and how you overcame it