PAS have produced the following resources you may find helpful on adult baptism by immersion. They are free to download.
A note about baptism by immersion for adult believers: Prospects Across Scotland works with many different denominations and are aware that churches have different theology and practices regarding baptism, such as infant baptism, or sprinkling of adults. We do not endorse one way over another. These resources have been produced to support those churches who practice immersion baptism of adult believer. We may be able to help you if you require different resources.
Adult Baptism Guidance for church leaders
All about Baptism Easy Read booklet
All about Baptism Easy Read powerpoint