This isn't straightforward but I'll try to explain:
Lifetime Allowance (LTA) is currently fixed at £1,073,100 unless you have protection (individual/fixed) which sound unlikely from your post.
If you've already used 96% of your Lifetime Allowance (LTA) you have crystallised £1,030,176 leaving £42,924 reaming. This is important as it means that you will only be able to draw 25% of this tax free regardless of the value of the pension benefit.
Any benefits taken above the LTA will be taxed. If taken as 'income' you'll pay 25% LTA tax charge + your marginal rate if income tax. As a basic rate tax payer this would represent 45% in total. The alternative would be to take benefits as a lump sum (if offered) but this would attract an LTA tax charge of 55%. In your situation, it is likely that 'income' with a small element of tax free cash £10,731 (25% of the available LTA remaining) may be sensible. It is likely that the pension provider will tell you what the maximum tax free cash you can get is and therefore the rest would be taken as income and the LTA tax charge applied.
You 'may' also have the option of transferring the defined benefit pension out, giving up the valuable 'safeguarded benefits'. Whilst this would not be sensible in the vast majority of cases it should be considered, if only to dismiss. An example of when this could be sensible would be if you did not have a 'need' for the additional income. If you have sufficient income already then the 'benefit' (income) really isn't a great option for you. Transferring into a personal pension arrangement (SIPP) could offer you greater death benefits, I say you, ultimately this would be for your beneficiaries and you/the pot would still be liable to the LTA... simply put, there's no avoiding it!