Yes you have to drop the tank,

 

Replaced the in tank pump with Walbro GSL 393 exterior pump 4 years ago. I removed the in tank unit, made modifications, run a 3/8 copper tube to within 1/2 inch of the tank bottom. Mounted the pump and filter on the inside of the frame rail, the pump pulls through the filter, thought this might be a problem, but no, took off without need for priming. have 31,000 miles on the pump, made in the USA.