Cryogenic Engine Pack [0.1.9] Mod will give you some new rocket engines, you can use their by easy way. This rocket engines is run on Liquid Hydrogen and Oxidizer, it’s a special of this mod. Have many models for you choose, detail is have total six models two in each of the 1.25, 2.5 and 3.75m sizes. These engines have better fuel efficiency than the KSP 1.0 stock engines, up to 455s, but beware! They’re more expensive and produce less thrust per unit weight. In addition, liquid hydrogen is less dense than liquid fuel, so for the same Delta-V, you will need more tanks.
To store your liquid hydrogen fuels, author has provided ModuleManager/InterstellarFuelSwitch configs that allow you to change the contents of stock tanks between LF/O, LH2/O, LF, O and LH2. These should work with most mod tanks, but no promises.