Witam jak zainstalować tego moda sitemap vbseo który znajduje się w dziale download do 3.8?

Pliki z katalogu 'upload' zamieszczasz na FTP, produkt .xml importujesz przez menadżera, na koniec dodajesz regułkę do ktaccess (jeśli korzystasz z apache/litespeed). Czyli tak jak w przypadku każdej innej modyfikacji.

a co zrobić żeby wyświetlało mi te sitemap? pobrałem vbsoe i chce odemnie jakiś pass do vbseo nie kumam o co z tym sitemap chodzi

Musisz ustalić swoje hasło w panelu administratora (dostęp do sitemap'y):
AdminCP -> Opcje vB -> Opcje vB -> vBSEO Sitemap

Następnie po zalogowaniu się do domena.pl/vbseo_sitemap/ klikasz 'Run SItemap Generator'.

no ok to już zrobiłem, klikam w "Run SItemap Generator" wyskakuje okienko 'Are you sure? " klikam ok i pojawia się takie coś

Kod:

[homepage] [910.0Kb mem used] [0s (+0s)]
[SECTION START] forumdisplay [910.0Kb mem used] [0s (+0s)]
[forumdisplay] forum_id: 1, total threads: 0, pages: 1 [910.0Kb mem used] [0s (+0s)]
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[SECTION START] showthread [912.6Kb mem used] [0s (+0s)]
[archive homepage] [1,111.1Kb mem used] [0s (+0s)]
[SECTION START] forumdisplay archived [1,111.1Kb mem used] [0s (+0s)]
[SECTION START] showthread archived [1,119.0Kb mem used] [0s (+0s)]
[SECTION START] member [1,233.3Kb mem used] [0s (+0s)]
[SECTION START] polls [1,275.3Kb mem used] [0s (+0s)]
[SECTION START] blogs [1,275.4Kb mem used] [0s (+0s)]
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[SECTION START] tags [1,275.7Kb mem used] [0s (+0s)]
[create sitemap file] filename: sitemap_1.xml.gz, number of urls: 676 [915.6Kb mem used] [0s (+0s)]
[create sitemap in text format] part #1 [915.6Kb mem used] [0s (+0s)]
[create sitemap index] filename: sitemap_index.xml.gz, number of sitemaps: 1 [916.0Kb mem used] [0s (+0s)]
Sitemap has been created. Click here to return [917.8Kb mem used] [2s (+2s)]

Niby sitemap zrobione ale nie ma np. tego pliku "sitemap_index.xml.gz" ani nic wiecej

google też nie może znaleźć tego pliku :/

Dodałeś odpowiednie reguły do pliku .htaccess?

a jakie i jak to zrobić?

Regułka jest podana w plikach modyfikacji. Jeśli nie utworzyłeś jeszcze pliku .htaccess po prostu zamieść gotowy (z folderu 'htaccess') na serwerze (w głównym katalogu Twojego forum).