RL Lemke on the K1600fforum.com forum sells a Superplug which solves that problem. It's basically the upper drain plug with a 1/4" socket welded to the end of it which simplifies the process, such that the village idiot can do it without worrying about it dropping into the crankcase. Both the LT and K1600 series bikes have their unique issues and DIY owners have devised tools to solve challenges. In the case of the LT, there is the BeemerBoneYard funnel for doing the servos and a cutout socket for another issue.
Although I loved my LT, I am a proponent of the K1600:
I frequent both this site and it's sister site and note that the K1600 owners do not cite issues about fuel line breakage; quick disconnects spewing fuel; top case latches failing; brake lines bursting; final drive crown bearing problems; windshield brackets breaking; low speed front wheel wobbling under deceleration; brake servos going out; oil on clutches; difficulty in changing out the air filter as the fuel tank needs to be removed first, etc., etc.
I do miss the level of technical expertise available on this forum for the LT, which is lacking on the K1600 and sincerely miss the fellowship that the Curve Cowboy Reunion brought to our predominately K-bike community.
I agree that the K1600 is improved in many areas compared to the LT. Unfortunately, it also lost ground in areas critical to my personal mission: long distance, all weather, two-up touring. I spend 90% of my miles cruising on two lanes or interstates and less than 10% canyon carving. For this use, 160 HP has no value compared to 117 as probably only 30 is being used during cruise. I ride in the rain and cold a lot in PA. The GTL soaks my hands and feet within minutes compared to hours on the LT. And my wife dislikes the seat, the "hidden" grab handles, the air buffeting and the bouncing Betty trunk.
These shortcomings far trump the advantages of the GTL for my mission. It is like Chevy coming out with a new Corvette with 100 more HP, better handling and better braking, but leaving out a heater and air conditioner. Some enthusiasts would still buy, but most would not give up that much comfort to gain a modest performance increase. That is how I view what BMW did with the GTL.
Most people who have moved to the GTL from the LT seem to be riders who ride primarily solo, primarily shorter canyon carving rides and in less rain and cold. For that mission, I absolutely understand the advantages of the GTL. For my mission, the LT is superior and I think the new Venture may be superior as likely will be the next Wing.
The good news is that BMW appears to be seeing the writing on the wall. The 2018 GTL appears to have modified the passenger seat, modified the fairing and mirrors for better wind and rain protection, possibly increased windshield size (can't tell from pictures alone) and added reverse. However, it remains to be seen if these are sufficiently effective. And the bouncing Betty trunk appears unchanged. I am awaiting full road tests and may take the wife and ride one.
I think the dismal sales figures support the assertion that BMW really missed the mark with the GTL. I spoke with one fairly high volume dealer who hates the K1600. He said they are hard to sell, but BMW forces him to take 1600s in order to get the other popular models. Late last fall he was selling an Exclusive for $4000 off list price and it still wasn't moving. The price would have to be well below $26,000 to get my attention. Maybe $22K would get me interested, but the wife would still not be interested at any price until they address the passenger comfort issues.