Firt step:find a bloodstalker or strong dinos i recomend spinos or rexes with imprint

Second step:find the magmasaur cave if You can't find it active one of the magma missions that That takes you to its location and them steal it

Warning:be carefull by is fire ball attacks they can do high damage and put You on fire killing You quickli

Step Three:ones You have the magmasaur egg just do it like any other egg

Step for:ones that is hatch claim it and it's your just be carefull and feed it with Ambergris or Sulfur and imprint

Final step:ones it's fully grow up just craft it's saddles and done You have your own magmasaur for farming very Efficient.

I hope the top helps You all and have fun suffering if You new on that map:D