Are they able to read and write in Spanish? That helps a lot. If they have iPads or other devices, they can translate assignments that way. I have 3rd graders who are do really well with that. Bilingual labels with pictures help too.
Basically provide as much multisensory input as possible: pictures, hand motions, physical objects, etc. Use simple language when possible so instructions are short and clear. Model EVERYTHING. And have them work with other students, especially if you have other Spanish-speaking students who also speak English.