Just take off the line next to it and tighten the loose one. There will be minimal fluid loss.
Might want to check your other lines though. Shouldn't take you that long at all to do.. 10 minutes at the most? Probably spend more time looking for your tools
Kubota B2630, '53 Farmall Super H, '47 Farmall AI, '44 Farmall A
The answer to your question: You need a flare nut wrench - a crow's foot flare nut wrench. Crow's foot is just the head of the wrench which you then turn with a socket wrench - great for tight spots. Flare nut variety is made to fit the fittings on your hydraulic hoses.