About translate code from assembler to C C

Step 1:(cca 1% of whoole time)
Basic Dissemble by IDA/HEXRAYS or snowman dissamble.
Step 2:(cca 10% of whoole time)
Fix code to compilable version.(by script for renaming and inserting tons code)
Step 3:(cca 15% of whoole time)
Rewrite graphics, files, mouse, keyboard and sounds procedures and other procedures.
Step 4:(cca 45% of whoole time)
Run this code and compare with output from code running in modified dosbox.
Fix any difference.
Steps 3 and 4 are performed simultaneously.
Step 5:(cca 30% of whoole time)
Cleaning,retyping structures, sortings procedures to files. Without this step can make only 32bit binary version. 64bit have different pointer size(8byte versus 4byte).
Step 6:
Add next resolutions and next improvements of code.