can't get back to bed so bear with me here my Legacy is elsewhere so I'm showing my SBE .. same general set-up...
you really don't need to remove the bolt handle ...


shown are the 4 basic parts: stock/receiver, bolt, barrel and fore...


attach the fore to the barrel..


dump the bolt into the receiver top/barrel...


mate the receiver/mag tube with the barrel/bolt and fore ...


shimmy the receiver/mag tube into the fore keeping the two slightly parallel.... you're gonna have to wiggle it around slightly ... its not going to break ...
 

keep sliding the barrel/fore back...


*important* - when you get this far, drop the bolt link or 'tongue' down so it rides the base of the receiver behind the trigger assembly...


now back the two together until they mate ... the action could be open or closed at this point depending how the bolt was seated in the receiver ... it makes no difference ...

 
now the gun should look like this ... stock/receiver and fore/barrel mated together...


all you have to do now is screw on the forend cap.