Basically it involves translations: Once you have your mRNA (which now only has exons) it then binds with rRNA (ribosomal RNA) It reads a start codon, and then the tRNA reads a complimentary anticodon which codes for a specific amino acid. Essentially the amino acids then interact elongate, and then you have a long chain of amino acids (primary structure of a protein)
Then there is a lot of folding, di-sulfide bridges and other interaction that then make the amino acids into a protein like haemoglobin (red blood cell)