First, look at what rate you will recover the VAT. It must be restored at the same rate at which it was deductible. If you acquired the asset before 2004, when the rate was 20%, then you have to use the same 20%. And this is despite the fact that currently such a rate does not exist. However, in the Tax law for this reason explanation there.
Having placed your bet, calculate VAT on fixed assets and intangible assets. Please note that you will have to restore not the whole deducting the value added tax, but only a part, proportional to residual value.
Next, decide the VAT on the remaining goods and materials. Their cost rate, multiply by the VAT. The resulting amount of pay in the budget.
The restored VAT enter in the sales book and purchase book do not touch. And you have to pay this VAT on the basis of the invoice on which this tax was accepted for deduction. This is evidenced by the letter №03-04-09/22 of the Ministry of Finance dated 16 November 2006.
The amount restored and paid VAT to consider as expenses for calculating profit tax. And - it costs the tax period that precedes the period when you went to the USN. If you are an entrepreneur, reduce the basis for calculating personal income tax, again for the previous period.
Don't forget about accounting and tax accounting. The restored VAT take, as mentioned above, the other costs.
Of course, recovery of the VAT will require you a lot of time and effort. But this procedure is spelled out in the tax legislation, and to avoid it, unfortunately, impossible.
Good luck with the business!