My sister is a USC and her husbands approved for his I-130 but after waiting 1 year for approval while wife was with kids in united states, they decided it was too long and he came to united states through Canada. They did not stamp/scan passport when he crossed with my sister,him and kids but looked at passports at crossing. They recently went to lawyer for help. He suggested that is was best to file I-485 while in united states instead of going back since he overstayed and could create issue. I filled out his I-130 forms and did all my N-600 forms that were approved. Is the I-485 something that a lawyer needs to handle or could it this be filed without much issue. Any things that make it difficult. Any help is appreciated.