Transferring tank

[Kilo]

Hi everyone,
I will be upgrading to a 40G from a current 20G. I plan on keeping all my existing fishes and some corals
What is the best way to do the transfer but there is a difficult consideration- the cabinet where the current tanks is , is wall mounted and cannot be move and i plan on putting my new at the same place as the existing tank

Options i have considered:
1) empty the existing tank to 20% and remove the big rocks. Keep the fishes and coral in the tank. Carry the exist tank to new location. Put back the rock and water.
2) buy a smaller tank. Move most of existing rock and all water over. Then move fish and coral that i want. Don't transfer the sand. Use back all equipment from current setup. Prep existing area for new tank

Fear on option 1: breaking the glass and weight
Fear on option 2: disturbances in biological filteration

Pls advice the best option and any other option.

I got a month to plan the transfer as my new tank will arrive in November

Thanks in advance

 

[sharpimage]

I would get some 5 gallon buckets from home depot. The 1t gallons of water is 120 pounds. It is carry able, but when you walk water splashes everywhere. I would get a few buckets, empty most if the water, rocks and fish. Then move the tanks around. Make sure you have heaters and air if it will be an extended time period