Public/Remove-TrelloCardMember.ps1

function Remove-TrelloCardMember {
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory, ValueFromPipeline)]
        [ValidateNotNullOrEmpty()]
        [object]$Card,
        
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$MemberId
        
    )
    begin {
        $ErrorActionPreference = 'Stop'
    }
    process {
        try {
            $uri = "$script:baseUrl/cards/{0}/idMembers/{1}?{2}" -f $Card.Id, $MemberId, $trelloConfig.String
            Invoke-RestMethod -Uri $uri -Method Delete
        } catch {
            Write-Error $_.Exception.Message
        }
    }
}