replacing one column in one record of a table

Replace one value in a table.pq

// replace bad name
let
    /* ignore this chunk */
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSspPUtJRMgRiI0NjQxMTpVidaKW0otQUkAgQGxsZm5iZGUPEczOLizPz0kHCQGxibGRqZgSVgphjAtJlbGKqFBsLAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [name = _t, customer = _t, UID = _t]),
    #"Changed Type" = Table.TransformColumnTypes(
        Source,{
            {"name", type text}, {"customer", Int64.Type}, {"UID", Int64.Type}
        }),

    /* select record, modify it, then call Replace

    you could use: https://docs.microsoft.com/en-us/powerquery-m/table-replacevalue

     */
    TargetRecord = Source{2}, // it is: [name="missing", customer=3, UID=43256234],
    NewRecord = [name="Terry", customer=3, UID=43256234],

    ModifiedTable = Table.ReplaceMatchingRows(
        Source,
        {
            {TargetRecord, NewRecord}
        }
    )


in
    ModifiedTable