"Zouden jullie liever een letterlijke vertaling willen?"
Translation:Would you rather have a literal translation?
You can't leave it out. The same sentence without "willen" doesn't make sense.
Would = zou(den) willen
The Dutch verb willen means to want. A literal translation of 'zouden jullie liever willen' is then 'would you rather want' which is no longer used in English and has become 'would you rather have'. The full expression is 'liever willen hebben' (rather want to have) but shortening to 'liever willen' (rather want) or 'liever hebben' (rather have) is common.