Solo 401k options for full-time W-2 employees

[Matthew Schwenke]

I'm a full-time employee with no recent self-employment income. My employer does not offer any retirement benefits and I will be in this job for several years. I already have a Roth IRA with stocks, and I know there's no good way to transfer that money out. So, I was planning on continuing to fund that for stocks/bonds and opening a Solo 401k for REI, but it appears as though the funds must come from self-employment income.

Can I contribute with my W-2 income?

Am I understanding the regulations correctly and is there an exception since I have no retirement account options through my job?

Any other suggestions of what to do?